Flame-retardant, antibacterial and hydrophobic multifunctional coatings on cotton fabrics via layer-by-layer self-assembly

The development of multifunctional fabrics remains a necessity of high priority to meet the growing requirements in practical applications. However, developing flame retardant fabrics with antibacterial property and hydrophobicity still faces many challenges. In this study, novel multifunctional cotton fabrics with flame retardancy, antibacterial property, and hydrophobicity were successfully prepared by layer-by-layer (LBL) self-assembly. A novel flame retardant and antibacterial linear polymer P(AA-ADMH) containing a nitrogen flame-retardant and an antibacterial based on N-halamine was synthesized. To obtain versatile functionalities, P(AA-ADMH), phytic acid (PA), and γ-aminopropyl triethoxysilane (APS) were introduced to cotton fabrics by LBL self-assembly. The limiting oxygen index (LOI) of the modified cotton fabrics increased to 27.3%, and the peak of heat release rate (PHRR) decreased by 29.3%. Due to the presence of N-halamine structure, the modified cotton fabrics exhibited significant antibacterial efficacy within 30 min. In addition, the contact angle of the modified cotton fabrics was around 110° which could reduce the adhesion of bacteria on the modified fabrics. This study provides a novel method to potentially develop multifunctional cellulose textiles for the fields of fire safety and other protection.